Geared Packing Nut System

ABSTRACT

The invention is a set of reduction gears constructed to aid the installation or removal of a packing nut or similar equipment part onto or from an oil field pump. A first gear is integrated onto a packing nut or other threaded part to a piece of oil field equipment. The first gear is placed in rotational contact with a second gear rotatably mounted on the surface of a fluid end. The second gear is a reduction gear which a worker can turn to thread the first gear of the packing nut. The invention includes a pawl set against the first gear prevent unwanted loosening of the packing nut during operations.

BACKGROUND OF THE INVENTION

Oil and natural gas field fracking operations require the pumping of large amounts of fracking fluids into the earth to fracture the formation using high performance pumping equipment Fracturing aids the release of natural gas and oil from the shale formations. These operations are performed under high pressure using fluids that contain chemicals and additives which abrade, corrode and otherwise wear down pumping equipment and pump components, such as sealing rings associated with packing nuts. As a result, it is necessary to perform maintenance on pumps frequently, including removing and replacing packing nuts. This maintenance is labor-intensive, unavoidable and time-consuming. In order to reduce costs, it is beneficial to find and implement strategies to reduce labor costs (the time needed to perform maintenance operations) and to minimize down time during operations. Fluid pumps must be robustly built. Because of the robust construction of the fluid pumps, most maintenance and repair performed on the pumps is labor intensive, generally requiring high torque applied on threaded parts and two or more workers for most operations.

For example, packing nuts in triplex and quintuplex fluid cylinders must be installed, removed, replaced and reinstalled regularly for routine pumping operations. Each packing nut is threaded into position in the fluid cylinder and can require 600 ft-lbs or more of torque either to set it into place or to remove it. The operation normally requires more than one worker to install or remove a packing nut using wrenches, levers and/or hammers. At least one company describes the installation and removal of such parts to require temporarily placing a sturdy lever in working position on a packing nut. A worker then strikes the lever with a hammer “two or three times” until the nut is either set or loosened, as indicated by the operation.

The high level of effort required to install or to remove packing nuts creates numerous opportunities for mishap, breakage of parts and/or injury to workers. The time-consuming nature of current technology drives up production costs and can delay operations. There is a need for a device which permits a single worker to install or remove high-torque threaded parts on a fluid end quickly, at the required torque and with a low risk of injury to workers, damage to the equipment or other mishaps. The described invention meets these needs.

BRIEF DESCRIPTION OF THE INVENTION

In this disclosure, reference is made generally to the invention working in conjunction with a packing nut commonly used on a fluid end. This reference is not a limitation and is made for convenience. The invention can be used to install or remove any threaded nut on a fluid end or other equipment by scaling up or down the size of the reduction gears described herein. In general in this disclosure, the first gear of the invention is described as fixedly attached to a packing nut. This is also not a limitation. The first gear may be fixedly attached or removably attached to the packing nut as preferred by the consumer or as indicated by the operation. A range of attachment means may be used so long as the invention is operable.

A packing nut on a fluid end, as commonly known in the industry, is a threaded nut approximately S inches in diameter. The packing nut is generally a hollow cylinder in shape. This shape permits the packing nut to hold in place various packing rings surrounding the pump plunger. The packing nut has an outer diameter that depends on the size of the threaded hole into which it is inserted as well as on the dimensions of the pump plunger. It has an inner diameter slightly larger than the outer diameter of the pumping cylinder so as to allow tight insertion of the pumping cylinder into the packing nut and packing rings. The invention comprises at least two gears further comprising a reduction gear set used in conjunction with the packing nut. The reduction gear set includes a first larger gear associated with the packing nut and a second smaller gear used to turn the first larger gear during use of the invention. In this disclosure the first larger gear is referred to as the “first gear” and the second smaller gear is referred to as the “second gear.” The first gear is in the form of a toothed hollow cylinder attached to or formed onto the packing nut. The inner diameter of the first gear is slightly larger than the inner diameter of the packing nut. Specifically, the inner diameter of the first gear is large enough not to make contact with the pump plunger held by the packing nut during fluid pump operations.

The first gear has a root diameter equal to or slightly greater than the outer diameter of the packing nut to permit the first gear and the second gear to operate together without further permitting the second gear to make contact with the outer surface of the packing nut. The outer diameter of the first gear must be suitable to allow the teeth of the first gear to make working contact with the teeth of the second gear. The first gear must be thick enough to allow the teeth of the first gear to engage the teeth of the second gear after the packing nut has been hand threaded into the threads of the fluid end.

The outer perimeter of the second gear is comprised of teeth sized to mate operationally with the teeth of the first gear. The reduction ratio of the two gears is typically about three to one, although this ratio is variable based on the specific application of the invention. The reduction ratio should not be so high as to cause or permit damage to parts when installing or removing the packing nut and it must be sufficient to permit operation by a single, average worker. The second gear is generally a toothed cylindrical solid and has projecting from it and centered on its longitudinal axis a shaped rod sized to fit in a shaped hole on the fluid end for using the invention on the surface of the fluid end. The shaped hole on the fluid end is positioned relative to the packing nut threaded hole to permit the two gears to mate operationally. The second gear has a thickness sufficient to permit the teeth of the second gear to make operational contact with the teeth of the first gear in order to install the packing nut into the packing nut hole. The shaped rod projecting from the second gear may be fixedly attached to the second gear or rotationally attached to the second gear. In one embodiment, the hole in the fluid end may be a smooth bore having a diameter suitable to permit rotatable insertion of the shaped rod in the shaped hole on the fluid end, and the shaped rod projecting from the second gear may be approximately a cylindrical rod. In this embodiment, the shaped rod is fixedly attached to the second gear. The shaped rod is inserted in the shaped hole of the fluid end and is free to rotate therein during operation. The shaped hole in the fluid end may be lubricated to permit smooth rotation of the shaped rod in the shaped hole of the fluid end. In another embodiment, the shaped rod may be fixedly attached to the second gear but either the shaped rod or the shaped hole in the fluid end comprises one or more ball bearing rings disposed on the rod or in the hole of the fluid end to aid rotation of the second gear rod, Therein, the shaped rod and shaped hole in the fluid end are sized to account for the use of the ball bearing rings). In a further embodiment, the shaped rod may be rotatably affixed to the second gear, such as by the use of ring bearings or other known designs. In that embodiment, the shaped rod may be removably affixed in the shaped hole in the fluid end through the use of mated threads on the shaped rod and in the shaped hole on the fluid end. In a preferred embodiment, the hole in the fluid end is sized to fit a seat comprising the shaped hole suitable to retain the shaped rod of the second gear.

The second gear has disposed on its upper face a shaped hole at its longitudinal axis for the insertion of a ratchet wrench or other drive wrench. Typically, a ½″ square hole is suitable for operation of the invention, although another size or shape may be suitable to use. The shaped hole is deep enough to permit the secure insertion of the drive wrench. In any embodiment, the rod must be affixed to the second gear so as to permit the shaped hole on the second gear to be properly disposed thereon. To operate the invention, the worker uses a drive wrench to drive the second gear anti-clockwise in order to drive the first gear clockwise, causing the threads of the packing nut to be driven into a suitable threaded hole on the fluid end. The second gear must be thick enough to permit the teeth of the second gear to engage the teeth of the first gear when the packing nut is hand threaded into the threaded hole of the fluid end and so only partially inserted into the threads. The thickness of each of the two gears must ensure the gears maintain working contact with each other as the packing nut is driven into the fluid end. When the packing nut is tightened to the proper torque, the second gear is removed and replaced with a pawl set between two teeth of the first gear to prevent loosening of the packing nut during operations of the fluid end. The pawl comprises a lever to hold itself in place between two teeth of the first gear and a rod extending perpendicularly from the pawl. The rod on the pawl fits into the same shaped hole as the shaped rod of the second gear and so must have the same shape as the shaped rod of the second gear. In the alternative, the rod of the pawl may be fitted into a second hole on the fluid end.

FIGURES

FIG. 1 depicts a perspective view of a packing nut known in the industry.

FIG. 2 depicts a side view of a packing nut with a first gear affixed to it.

FIG. 3 depicts a perspective view of the first gear and the packing nut showing a tab and hole method of connecting those parts.

FIG. 4 depicts a top view of the first gear and packing nut.

FIG. 5 depicts a side view of the first gear without a packing nut affixed.

FIG. 6 depicts a top view of the second gear.

FIG. 7 depicts a side view of the second gear.

FIG. 8 depicts a side view cross-section of the first gear and packing nut in hand-tightened position in the threads of the fluid end in working contact with the second gear.

FIG. 9 depicts a side view cross-section of the first gear and the top of the packing nut final position in the threads of the fluid end with the first gear in working contact with the second gear.

FIG. 10 depicts a side view of the pawl.

FIG. 11 depicts a top view of the pawl without the rod attached.

FIG. 12 depicts a top view of the pawl in position with the first gear,

DETAILED DESCRIPTION OF THE INVENTION

The invention described herein is not limited to the embodiments disclosed but may be practiced in any form identified by the disclosure.

Referring first to FIG. 1, a packing nut 100 known in the industry is depicted. The packing nut 100 is a hollow cylinder in form with an inner diameter 102 and an outer diameter 103. In this form of common packing nut, a plurality of holes 104 are disposed on a collar 106 positioned proximal to the threads 105 of the packing nut. Inner diameter 102 is sized to fit a fluid end plunger (not depicted) and outer diameter 103 is sized to mate with the threaded hole of a fluid end. This form of packing nut is hand threaded into the threaded hole of a fluid end. To finish tightening, a worker must insert a lever, not depicted, radially into one of the holes 104 to tighten the packing nut. The lever, extending radially from hole 104 of packing nut 100, provides leverage to the worker. Further tightening may be accomplished by hitting the inserted lever with a hammer in the proper direction. Removal of the packing nut 100 from its tightened position may also require the use of a lever inserted into one of the holes 104 with one or more workers turning the packing nut 100. Again, this may include hitting the lever inserted into a hole 104 on the packing nut 100 with a hammer to loosen the packing nut 100. Holes 104 of the packing nut 100 may be disposed diametrically to permit a lever to be inserted through one hole 104 along a diameter of the packing nut 100 and into a second hole 104 radially across from the first hole 104 to permit two workers to remove or install the packing nut 100 using a long lever sufficient to accommodate both workers. While potentially helpful, a two-worker operation immediately doubles the cost of performing maintenance.

The risks created by this form of loosening and tightening a packing nut 100 is evident. Hitting an inserted lever with a hammer may cause metal fatigue, resulting in shards from broken. packing nuts 100 flying and injuring workers. Inserted levers may come loose from the packing nut 100, likewise flying and injuring workers. Striking metal on metal may create dangerously loud noise, requiring workers to use ear protection. This creates additional safety issues at a job site.

Referring now to FIG. 2, a side view of the combined packing nut and first gear 200 of the present invention is depicted. For clarity, the term “packing nut and first gear” is the name of the part defined as part number 200 in this disclosure. In this FIG. 2, the first gear is integrated into the packing nut, although this is not required. In another embodiment, a first gear 301 may be removably attached to a packing nut 300, as depicted in FIG, 3. In this disclosure, the combined packing nut and first gear 200 is the form described unless noted otherwise.

Referring still to FIG. 2, threads 205 of the packing nut and first gear 200 are depicted. The thread height 204 of the threads 205 of the packing nut and first gear 200 is also depicted, along with the tooth height 206 of the plurality of teeth 207 on packing nut and first gear 200. Each of the teeth 207 may be referred to as a tooth also numbered 207. The thread height 204 is determined by the depth of the threaded hole in the fluid end into which the packing nut and first gear 200 must be threaded.

Referring to FIG. 3, a packing nut and a first gear may be made as separate but attachable parts. Specifically, FIG. 3 depicts a threaded packing nut 300 and first gear 301. This packing nut 300 has an upper surface 302 on which is disposed a plurality of attachment and alignment holes 305. The first gear 301 has a bottom surface 308 on which are disposed a corresponding plurality of projections 309 designed to fit into the attachment holes 305 of the packing nut 300. The plurality of attachment holes 305 and projections 309 may be cylindrical, hemispherical, square, rectangular or other mateable shape. While an attachment hole 305 and projection 309 method of connecting the separate packing nut 300 and first gear 301 is depicted in FIG. 3, any suitable method of connecting those parts that permits working contact between them may be used. For example, a first gear 301 may be bolted to a packing nut 300 by use of a plurality of bolts (not depicted) tightened into suitable threaded holes (not depicted) in the packing nut 300 and using through holes (not depicted) in the first gear 301.

Referring now to FIG. 4, the packing nut and first gear 200 is designed to permit the packing nut element of part 200 to make working contact with a plunger (not depicted) used in the fluid end to pump fluids through the fluid end. At the same time, the first gear element of part 200 is designed not to make contact with a fluid end plunger. Specifically, as depicted first in FIG. 4, packing nut and first gear 200 has two inner diameters- a smaller inner diameter 405 of the packing nut element and a larger inner diameter 406 of the first gear element. The smaller inner diameter 405 is sized to correspond to the diameter of the fluid end plunger. The larger inner diameter 406 is designed to ensure the first gear element of part 200 does not interfere with fluid end operations or to make contact with the fluid end plunger but is designed instead to permit easy installation and removal of the packing nut and first gear 200. The orientation of the packing nut and first gear 200 in FIG. 4 depicts the first gear element of part 200 toward the viewer and the packing nut element of part 200 away from the viewer.

The different diameters 405 and 406 of the packing nut and first gear 200 is also depicted in FIG, 8, which depicts a cutaway side view of the packing nut and first gear 200 in position in threaded hole 801 of a fluid end 800. FIG. 8 shows the inner diameter 405 of the packing nut element of part 200 is the same throughout the packing nut element of part 200. This permits full contact between a fluid end plunger and the inner wall of the packing nut element of part 200. Then, in the present embodiment, the inner diameter 406 of the first gear element of part 200 is both larger than inner diameter 405 and increases along the length of the first gear element of part 200. In another embodiment, a single, larger inner diameter 406 is disposed in the first gear element of part 200 incorporating vertical walls inside the first gear element of part 200. In that embodiment, a flat horizontal surface connects the larger inner diameter 406 of the first gear element of part 200 to the smaller inner diameter 405 of part 200. Other configurations of the inside surfaces of part 200 are possible so long as in each embodiment the inner diameter 406 of the first gear element of part 200 is larger than the inner diameter 405 of the packing nut element of part 200.

In general, when threading a packing nut into a threaded hole of a fluid end, whether a commonly known packing nut or the packing nut element of the present invention, the packing nut threads are generally hand-tightened to about one half the height of the threads on the packing nut, After that, compression of the sealing rings associated with the packing nuts resists further hand-tightening. Thereafter, workers require a mechanical advantage to complete the operation. This invention incorporates that general condition.

FIG. 5 depicts the first gear 501 portion of the packing nut and first gear 200 to show more clearly the design thereof.

As depicted in FIG. 8 and FIG. 9, the packing nut and first gear 200 is hand threaded into a threaded hole 801 on the fluid end 800, causing the threads 205 of the packing nut and first gear 200 to be threaded partially into the threaded hole 801. The thread height 204 of the packing nut and first gear 200 are constructed to ensure and allow the teeth 207 of the packing nut and first gear 200 to make working contact with the teeth 601 of the second gear 600, as also depicted in FIG. 9, when the packing nut and first gear 200 is hand-tightened into threaded hole 801,

Referring in addition to FIG. 6, the top view of a second gear 600 is depicted. Second gear 600 is also depicted in working position in FIG. 8 and FIG. 9. Second gear 600 has disposed thereon a plurality of teeth 601 sized to mate workably with the teeth 207 of the packing nut and first gear 200, At the axial center of the second gear 600 is disposed a shaped hole 602 sized to fit a tool, such as a ½″ ratchet wrench or torque wrench, used to drive the second gear 600. Referring further to FIG. 7, a side view of the second gear 600 is shown. This figure depicts the tooth height 701 of teeth 601 of the second gear 600. The tooth height 701 of the teeth 601 is sized to mate workably with the teeth 207 of the packing nut and first gear 200 as the packing nut and first gear 200 is threaded into the fluid end 800 as depicted in FIG. 8 and FIG. 9. For clarity, the tooth height 701 of second gear 600 must extend high enough above the top surface of the fluid end 800 so as to be able to engage at least the bottom of teeth 207 of the packing nut and first gear 200 sufficiently to operate without breaking or slipping.

Referring to FIG. 7 and FIG. 9, disposed concentrically on the imaginary longitudinal axis 703 of the second gear 600 is a shaped rod 702. In a preferred embodiment, a shaped rod 702 is fixed with respect to second gear 600. Shaped rod 702 is inserted into a shaped hole 901 depicted in FIG. 9. Shaped hole 901 comprises a shaped, generally cylindrical bore to permit easy rotation of the second gear's 600 shaped rod 702 in shaped hole 901. in an alternate embodiment, shaped rod 702 and/or shaped hole 901 may have disposed thereon or therein one or more ball bearing rings (not depicted) to aid smooth rotation of the second gear 600. As depicted in FIG. 8 and FIG. 9, shaped hole 901 is disposed within an insertable seat 910 in shaped hole 901, In the preferred embodiment, seat 910 is used to prevent the flow of lubricants through the fluid end 800 when desired.

In another embodiment, axle 702 is affixed to second gear 600 so as to permit second gear 600 to rotate with respect axle 702. In this embodiment, axle 702 and hole 901 may each be threaded. In operation, axle 702 is threaded into hole 901. Once in place, second gear 600 is used to drive first gear 200 as in other embodiments.

Referring to FIG. 8 and FIG. 9 together, the operation of the invention is described: a fluid end 800 has disposed on it a threaded hole 801 sized to fit a threaded packing nut and first gear 200. The threads 205 of a packing nut and first gear 200 are hand-threaded by a worker into threaded hole 801. Hand tightening is done until the bottom edge of the teeth 207 of the packing nut and first gear 200 are low enough above the surface of the fluid end 800 top to engage the teeth 601 of the second gear 600 sufficiently to allow further tightening of the packing nut and first gear 200 by driving it with the second gear 600. Once hand-tightened, the worker inserts axle 702 of the second gear 600 into hole 901 on the fluid end 800, thereby engaging teeth 207 to teeth 601. Hole 901 is positioned to permit the teeth 207 of the packing nut and first gear 200 to engage workably the teeth 601 of the second gear 600,

Next, a worker inserts the driver of a drive wrench, such as a ½″ ratchet wrench (not depicted) into hole 602 of second gear 600 and uses the drive wrench to drive second gear 600 counter-clockwise. With the teeth 601 of second gear 600 engaged workably with the teeth 207 of packing nut and first gear 200, the second gear 600 is then rotated by a worker to drive the packing nut and first gear 200 clockwise into the threaded hole 801. A 3 to 1 gear ratio between the packing nut and first gear 200 and second gear 600 permits a single worker applying 200 ft-lbs of torque on the ratchet wrench to set the packing nut and first gear 200 in the threaded hole 801 with the necessary 600 ft-lbs of torque commonly needed to secure a packing nut in place in a fluid end.

Removal of the packing nut and first gear 200 requires a reversal of the operation. A worker uses a drive wrench to drive the second gear 600 clockwise to turn the packing nut and first gear 200 counter-clockwise out of the threaded hole 801.

When the packing nut and first gear 200 is tightened in place, the second gear 600 is removed from the top of the fluid end 800.

Referring now to FIG. 10 and FIG, 11, a pawl 1000 is identified. Pawl 1000 has disposed at one end and projecting outward from it a partly threaded rod 1001. Pawl 1100 further comprises a lever arm 1201. Referring to FIG. 13, the partly threaded rod 1101 of pawl 1100 is inserted into hole 1001 on top of the fluid end 900, Lever arm 1201 of the pawl 1100, is placed between two adjacent teeth 207 of packing nut and first gear 200 to ensure the packing nut and first gear 200 does not loosen during pumping operations. The threads on the partly threaded rod 1101 of pawl 1100 extend through hole 1001 on fluid end 900 so as to permit a nut (not depicted) to be threaded thereon to secure the pawl. 1100 in place. 

We claim:
 1. A geared packing nut assembly for a fluid end suitable to insert a packing nut into or to remove a packing nut from a the fluid end comprising: a threaded packing nut operatively integrated with a first toothed gear in which the threads of the packing nut are mated to the threads of a corresponding hole on a fluid end used for pumping fluids into a well hole and in which the threads of the packing nut have a height and in which the teeth of the first toothed gear have a thickness and in which the packing nut has an inner diameter sized to fit a fluid end plunger for the fluid end and in which the first toothed gear has an inner diameter larger than the inner diameter of the packing nut; a second toothed gear in which the teeth of the second toothed gear have a thickness and in which the second toothed gear further comprises a rod projecting from the longitudinal axis of the second toothed gear suitable to insert into a suitable hole on the fluid end.
 2. The geared packing nut assembly of claim 1 in which the height of the teeth of the second gear, the height of the threads of the packing nut element and the height of the teeth of the first toothed gear permit the teeth of the first toothed gear, when the threads of the packing nut are hand threaded into a fluid end, to engage the teeth of the second gear.
 3. The geared packing nut assembly of claim 1 in which the threads of the packing nut permit hand-tightening of the geared packing nut assembly into the threads of the fluid end sufficient for the teeth of the first toothed gear to engage the teeth of the second toothed ger.
 4. (canceled)
 5. The geared packing nut assembly of claim 1 which further comprises a pawl further comprising a rod suitable to insert into a hole on the fluid end permitting the pawl to hold the first toothed gear in place.
 6. (canceled)
 7. (canceled) 